This invention relates generally to apparatus and methods for administering drugs and other substances intravenously into a patient. The invention relates more particularly to apparatus and methods for assuring that a prescribed dosage is actually administered to the patient.
There are significant difficulties in assuring administration of prescribed dosages to patients. The difficulties arise from the various units in which prescriptions are given and from the units that define the dosage rates that are administered by typical intravenous equipment. Drug administration rates are commonly prescribed in milligrams, micrograms or UNITS per unit of time. A UNIT is a measure of an amount of a drug. The time is usually given in hours or minutes. The patient's body weight in kilograms or pounds may be a factor in the drug administration rate. The patient's body surface area, commonly given in square meters, may also be considered in determining the drug administration rate.
Actual drug administration rates are determined by a pump setting that is normally a certain number of drops per minute or cubic centimeters per hour. A physician will normally prescribe a drug administration rate in units of measure with which he is familiar or in units recommended by the drug's manufacturer. The nurse or other technician who actually sets the pump rate must convert the prescribed drug administration rate into an appropriate number of drops per minute or cubic centimeters per hour so that the pump may be set at a value appropriate for delivering the prescribed amount of drug to the patient.
Present methods for determining the pump rates include hand calculations and calculations using general purpose calculators. These methods are subject to error with results that are sometimes catastrophic.
Therefore, there is a need in the art for a simple, reliable device for calculating drug dose rates to facilitate administration of prescribed dosages.